The relationship between cannabis and schizophrenia : a genetically informed perspective

© 2021 Society for the Study of Addiction..

BACKGROUND AND AIMS: While epidemiological studies support a role for heavy, high-potency cannabis use on first-episode psychosis, genetic models of causation suggest reverse causal effects of schizophrenia on cannabis use liability. We estimated the genetic relationship between cannabis use disorder (CUD) and schizophrenia (SCZ) and tested whether liability for CUD is causally associated with increased liability to SCZ while adjusting for tobacco smoking.

DESIGN: This study used summary statistics from published genome-wide association studies (GWAS). We used genomic structural equation modeling, latent causal variable analysis, and multivariable Mendelian randomization to examine genetic relationships between CUD, cannabis ever-use, ever-smoked tobacco regularly, nicotine dependence and SCZ, and to test for a causal relationship between liability to CUD and liability to SCZ.

SETTING: Genome-wide association studies were published previously as part of international consortia.

PARTICIPANTS: Sample sizes of the GWAS summary statistics used in this study ranged from 161 405 to 357 806 individuals of European ancestry.

MEASUREMENTS: Genome-wide summary statistics for CUD and SCZ were the primary measurements, while summary statistics for cannabis ever-use, ever-smoked tobacco regularly and nicotine dependence were included as additional variables in the genomic structural equation models and the multivariable Mendelian randomization analyses.

FINDINGS: Genetic liability to CUD was significantly associated with SCZ [β = 0.29, 95% confidence interval (CI) = 0.11, 0.46, P = 0.001], even when accounting for cannabis ever-use, ever-smoked tobacco regularly and nicotine dependence as simultaneous predictors. We found mixed evidence of a causal relationship, with the latent causal variable analysis finding no evidence of causality (genetic causality proportion = -0.08, 95% CI = -0.40, 0.23, P = 0.87) but the multivariable Mendelian randomization analyses suggesting a significant, risk-increasing effect of CUD on liability to SCZ (β = 0.10, 95% CI = 0.02, 0.18, P = 0.02), accounting for the additional risk factors (cannabis ever-use, ever-smoked tobacco regularly and nicotine dependence).

CONCLUSIONS: Genetic liability for cannabis use disorder appears to be robustly associated with schizophrenia, above and beyond tobacco smoking and cannabis ever-use, with mixed evidence to support a causal relationship between cannabis use disorder and schizophrenia.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:116

Enthalten in:

Addiction (Abingdon, England) - 116(2021), 11 vom: 06. Nov., Seite 3227-3234

Sprache:

Englisch

Beteiligte Personen:

Johnson, Emma C [VerfasserIn]
Hatoum, Alexander S [VerfasserIn]
Deak, Joseph D [VerfasserIn]
Polimanti, Renato [VerfasserIn]
Murray, Robin M [VerfasserIn]
Edenberg, Howard J [VerfasserIn]
Gelernter, Joel [VerfasserIn]
Di Forti, Marta [VerfasserIn]
Agrawal, Arpana [VerfasserIn]

Links:

Volltext

Themen:

Cannabis
Genome-wide association study
Genomic structural equation modeling
Journal Article
Latent causal variable model
Multivariable Mendelian randomization
Research Support, N.I.H., Extramural
Schizophrenia
Tobacco

Anmerkungen:

Date Completed 08.10.2021

Date Revised 14.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/add.15534

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM325034338